-- LUA Script - precede every function and global member with lowercase name of script + '_main'
local Q = require "scriptbank\\quatlib"
local U = require "scriptbank\\utillib"
local P = require "scriptbank\\physlib"

local rad  = math.rad
local deg  = math.deg
local abs  = math.abs
local cos  = math.cos
local min  = math.min
local max  = math.max
local atan = math.atan2

local posList = 
{ 
  [ 'Pressure Gauge' ] = { typ = 'Base' },
  [ 'Gauge Needle' ] =
		{ base = 'Pressure Gauge', typ = 'Needle',
		  xo = -2.135, yo = 12.171, zo = 0 },
  [ 'Joint (Pipe Work)' ] = { typ = 'Base' },
  [ 'Stop Valve Tap (Pipe Work)' ] =
		{ base = 'Joint (Pipe Work)', typ = 'Valve',
		  xo = 7, yo = 16, zo = 0 },
}

local dynEnts = {}

function gauges_init_name( e, name )
	Include( "quatlib.lua" )
	Include( "utillib.lua" )
	Include( "physlib.lua" )
	dynEnts[ e ] = { name = name, state = 'init' }
	-- set health to a stupidly high value
	SetEntityHealthSilent( e, 1000000)
end

local function findBase( de )
	for k, v in pairs( dynEnts ) do
		if posList[ v.name ].typ == 'Base' and 
		   v.state == 'ready' and
		   v.atts[ de.name ] == 0 then
			return k
		end
	end
end

local function gimbalAdj( ya )
	if abs( ya - 90 ) < 0.001  then	
		return 89.999 
	elseif abs( ya + 90 ) < 0.001 then
		return -89.999
	end
	return ya
end	

local function positionEnt( e, x, y, z, xa, ya, za )
	CollisionOff( e )
	ResetPosition( e, x, y, z )
	ya = gimbalAdj( ya )
	ResetRotation( e, xa, ya, za )
	CollisionOn( e )
end

local function GaugesGetPressure( name )
	for k, v in pairs( dynEnts ) do
		if v.name == name then 
			return v.pressure
		end
	end
end

local function GaugesSetPressure( name, pressure )
	for k, v in pairs( dynEnts ) do
		if v.name == name then 
			v.pressure = pressure
			v.state = 'rotating'
			break
		end
	end
end

local function processPressure( change, moveAmount )
	if change then
		local pressure = GaugesGetPressure( 'Gauge Needle' )
		
		if moveAmount < 0 then
			if pressure > 0 then
				GaugesSetPressure( 'Gauge Needle', pressure - 1 )
			end
		else
			if pressure < 100 then
				GaugesSetPressure( 'Gauge Needle', pressure + 1 )
			end
		end
	end
end

local lastTime   = 0
local moveAmount = 0

function gauges_main( e )
	local de = dynEnts[ e ]
	if de == nil then return end
	
	local typ = posList[ de.name ].typ
	
	local timeNow = g_Time
	
	if timeNow > lastTime + 20 then
		moveAmount = ( timeNow - lastTime ) / 20
		lastTime = timeNow
	end
	
	if  de.state == 'done' then
		-- no more processing needed for this entity
		return
		
	elseif
	   de.state == 'init' then
		
		if typ == 'Base' then
			-- first work out what our attachments are
			de.atts = {}
			
			for k, v in pairs( posList ) do
				if v.typ ~= 'Base' and v.base == de.name then
					de.atts[ k ] = 0
				end
			end
			de.x, de.y, de.z, de.xa, de.ya, de.za = GetEntityPosAng( e )
			
			-- now mark ourselves as ready
			de.state = 'ready'
			
		else
			-- must be attachment so look for a base that is ready
			-- to accept us
			local base = findBase( de )
			if base == nil then return end
			
			local b = dynEnts[ base ]
			b.atts[ de.name ] = e
			local p = posList[ de.name ]
			local xo, yo, zo = U.Rotate3D( p.xo, p.yo, p.zo, 
			                               rad( b.xa ), rad( b.ya ), rad( b.za ) )
			de.x, de.y, de.z = b.x + xo, b.y + yo, b.z + zo
			positionEnt( e, de.x, de.y, de.z, b.xa, b.ya, b.za )
			de.obj = g_Entity[ e ].obj
			de.baseObj = g_Entity[ base ].obj
			de.baseEnt = base
			de.state = 'idle'
			
		end
		
	elseif
	   de.state == 'ready' then
		-- check if we have all attachments
		for k, v in pairs( de.atts ) do
			if v == 0 then 
				PromptLocal( e, "Don't have a " .. k .. '!' ) 
				return 
			end
		end
		de.state = 'done'
		
	elseif
	   de.state == 'idle' then
		if typ == 'Needle' then 
			de.pressure = 0
			de.angle = -145
			de.state = 'rotating'
			local _, _, _, xa, ya, za = GetEntityPosAng( e )
			de.quat =  Q.FromEuler( rad( xa ), rad( ya ), rad( za ) )
		
		elseif 
		   typ == 'Valve' then
			de.state = 'off'
			de.angle = 0
			local _, _, _, xa, ya, za = GetEntityPosAng( e )
			de.quat =  Q.FromEuler( rad( xa ), rad( ya ), rad( za ) )
		end
		
	elseif
	   de.state == 'rotating' then

		local tgtAng = -145 + de.pressure * 2.9
		
		if de.angle > tgtAng then 
			de.angle = de.angle - moveAmount
		elseif
		   de.angle < tgtAng then
		    de.angle = de.angle + moveAmount
		else
			de.state = 'stationary'
		end
		
		turnQ = Q.FromEuler( -rad( de.angle ), 0, 0 )
		
		xa, ya, za = Q.ToEuler( Q.Mul( de.quat, turnQ ) )
		positionEnt( e, de.x, de.y, de.z, deg( xa ), deg( ya ), deg( za ) )

	elseif 
	   de.state == 'off' then
		-- detect player
		if U.PlayerLookingNear( e, 80, 30 ) then
			Prompt( "LMB to open valve" )
			if g_MouseClick == 1 then
				de.state = 'turning'
				de.tgtAng = 420
			end
		end
			
	elseif 
	   de.state == 'on' then
		-- detect player
		if U.PlayerLookingNear( e, 80, 30 ) then
			Prompt( "LMB to close valve" )
			if g_MouseClick == 1 then
				de.state = 'turning'
				de.tgtAng = 0
			end
		end
		
	elseif
	   de.state == 'turning' then
		if de.tgtAng == 0 then
			if de.angle > de.tgtAng then 
				de.angle = de.angle - moveAmount
				processPressure( de.angle < 300, -moveAmount )
			else
				de.state = 'off'
			end
			
		else
			if de.angle < de.tgtAng then
				de.angle = de.angle + moveAmount
				processPressure( de.angle > 100, moveAmount )
			else
				de.state = 'on'
			end
		end
		
		
		turnQ = Q.FromEuler( 0, -rad( de.angle ), 0 )
		xa, ya, za = Q.ToEuler( Q.Mul( de.quat, turnQ ) )
		positionEnt( e, de.x, de.y, de.z, deg( xa ), deg( ya ), deg( za ) )
		
	end
	
end